Regenerated Nerve Defects with a Nerve Conduit Containing Dental Pulp Stem Cells in Pigs: An Immunohistochemical and Electrophysiological Evaluation.

Dental pulp stem cells (DPSCs) present an exciting new tool in the field of peripheral nerve regeneration due to their close embryonic origin. In this study, we examined their potential in pigs, using biodegradable collagen conduits filled with DPSCs. To our knowledge, this is the first time DPCSs are tested for peripheral nerve regeneration in such large animal model. The second lateral incisor was extracted from every animal's lower jaw and stem cells were isolated and cultured. The collagen nerve conduits containing the DPSCs were subsequently transplanted into the transected fifth and sixth intercostal nerves, while the seventh intercostal nerve was used as a control and no stem cells were added on the respective collagen conduit. A histological examination was performed on the 3rd and 6th postoperative months and showed the gradual development of neural tissue and immunohistochemical expression of neuron-specific enolase. An electrophysiological study was performed on the 6th postoperative month and showed similar potentials between the stem cell infusion region (5 ± 0.04 units) and their proximal stumps (5 ± 0.05 units) and slightly smaller potentials in the respective distal stumps (4 ± 0.045 units). The nerves where DPSCs were injected exhibited morphological and functional recovery, in contrast to the control nerves where no recovery was detected; thus, there is a first evidence of the therapeutic potential of DPSCs in peripheral nerve regeneration.